Voters of the two major parties, Labour and the Conservatives, follow fairly predictable patterns. As predicted by the literature and shown with Republican and Democrat voters, Conservatives are significantly more conscientious than the mean respondent, the opposite being true for Labour voters. The average Conservative voter is also significantly less open to experience though, surprisingly, Labour voters tended to be barely any more open to experience than the average voter in 2015.

Emotional instability, the third personality trait most commonly shown to affect party choice, follows a predictable pattern, with Conservative voters shown to be less unstable than the mean voter, and Labour voters more unstable. Labour voters are also shown to be more agreeable than the mean and, in fact, the most agreeable group of voters, while Conservatives are the most extroverted, as predicted by the literature. (...)

UKIP and Green voters are the most closed and open-minded respectively, suggesting that attitudes to immigration are particularly affected by this trait. Green voters are far less conscientious of social norms than any other party, with UKIP voters around the national average. Liberal Democrat voters rank in the middle of all five parties on both traits. On emotional instability, UKIP voters are more neurotic than we might expect and Green voters scores especially highly on this trait. Finally, on agreeableness and extroversion, the two traits with the least evidence of association with party choice in the literature, we see interesting results. Green, Liberal Democrat and UKIP voters are all less agreeable and less extrovert than the voters of the major two parties. Disagreeableness and introversion may therefore be key personality traits of the protest voter. (...)

The expected results were replicated amongst Labour and Conservative voters at the 2015 UK General Election. The newer parties less consistently follow these associations. Either their voters are more extreme, in the case of very high openness amongst Greens and low openness amongst UKIP members, or voters of all newer parties vary together from the major two parties – with Greens, Kippers and Lib Dems sharing a tendency for disagreeableness and introversion amongst their voters. Unsurprisingly, individuals less likely to go with the flow and less energized by big social organisations have been the first to jump ship from Labour and the Conservative party to the protest parties.